Colored text shadow in /title is wrong after a newline

How to reproduce

/titleraw @a title {"rawtext":[{"text":"§0line 1\nline 2"}]}

Expected appearance
Both lines are very dark

Observed appearance
Second line shadow is too bright

Notes

The correct behavior appears in chat. Other places (actionbar, sidebar, books, chat) don't have shadows, so it can't be determined if they are affected.